Laparoscopic and endoscopic surgical instruments are used to perform surgery without the need to make large incisions. These procedures are generally less invasive than conventional surgery. Surgical instruments useful in these procedures generally include a hollow probe inserted into the body, through which various scopes and other instruments may be inserted. Such instruments may include, for example, endoscopes, laparoscopes, clip appliers, microscissors, forceps, optical fibers connected to laser sources for hemostatic cutting or coagulation, electrode sets for electrocautery, as well as, suction and irrigation lines.
In addition, in such minimally invasive surgery it is often desired to irrigate an operative site with a sterile solution and then to withdraw or aspirate fluids from the surgical site under suction. The aspirated fluids can include, not only the irrigation solution, but also blood and other body fluids, tissue and fragments. Such irrigation of an operative environment poses two significant design hurdles. First, the fluid that is use to irrigate the operative site must be maintained as a sterile fluid. Second, the irrigation of an operative site requires pumping a large amount of liquid (up to three liters per minute) in a medical environment.
This irrigation and aspiration is typically achieved by use of an externally operated valve device and an elongated probe that is manipulated by the surgeon to control flows into and out of the operative site. These are referred to as to as “trumpet valves” because of the similarity of their look and feel to a trumpet.
The trumpet valves include key members on top of two adjacent and parallel valve barrels that can be selectively depressed by the surgeon against a compression spring. Depression of one key transmits irrigation fluid through the valve assembly and out through the endoscopic probe member to irrigate the surgical site. Depression of the other key opens a suction line to permit fluids to be aspirated from the surgical site through the probe and valve. Aspiration vacuum is provided to the trumpet valve by a source of vacuum.
Irrigation fluid is provided to the trumpet valve by a pump. In one prior art system the pump itself is disposable which is extremely expensive. In other prior art pump systems the pump interacts with a pump cartridge. Such diaphragm pump cartridge assemblies typically include cassette body having an inner flow chamber disposed in a one-way fluid flow passageway. The front end of the chamber is closed off by a resilient diaphragm member. The front end of the cartridge cassette is provided with mateable quick disconnect features so that the cartridge cassette may be inserted into and mated with a mateable socket defined on an electronically controlled pump.
In accordance with the typical suction irrigation system of the prior art, the electronic control of the motor is independent from the suction and irrigation actuators on the irrigation valve and probe assembly. As a result, the pump frequently remains in an on condition and thereafter, at the initiation of irrigation flow, undesirable pressure may be developed on the irrigation fluid side which is released in a jet of irrigation fluid on actuation of the probe. The jetting of fluid is undesirable because it varies unexpectedly and results in a loss of control for the surgeon. In order to turn off the pump, the surgeon must turn away from the operative site to turn the pump on or off, or must communicate commands to additional surgical personnel, which may lead to a break in the surgeon's concentration or errors in communication which are also major disadvantages.
Moreover, the probe handle assembly typical in the prior art includes flow actuator valves of a non-trumpet valve type with a lever switch which has to be manually flipped on and off by the surgeon, usually using a second hand to do so.
In addition, it is desired that the irrigation system be able to deliver, on demand, controlled but relatively large quantities of irrigation fluid in a non-distracting manner under control of the surgeon. A major problem with the diaphragm members of the prior art is that they lack the resilient properties required to refill the pumping chamber with consistency and accuracy. In an effort to increase the return performance of the diaphragm, increases in diaphragm thickness or durometer have been attempted, however, these steps place additional strain on the piston and the pump, particularly on start up, which causes stress on the pump electronics.
What would be desirable is a suction irrigation system which place direct irrigation flow under the one handed control of the surgeon. What would be further desirable is a disposable suction irrigation cassette assembly that is capable of operating with a pump in a manner which delivers consistently controlled irrigation fluid volumes, at controlled rates and pressures under the control of the surgeon. Still further, what would be desirable is an irrigation system that is able to deliver, on demand, consistent and accurate quantities of irrigation fluid in a non-distracting manner under control of the surgeon. Additionally, the irrigation system should prevent the pump from burning itself out.